Canine influenza virus (CIV) was first detected in 2004 in racing greyhounds in Florida. Investigators learned that this new canine influenza developed when an equine influenza virus adapted to infect dogs. This was the first time that an equine influenza virus had been found to “jump” from horses to dogs. According to Dr. Cynda Crawford of the University of Florida College of Veterinary Medicine, canine influenza does not infect people, and there is no documentation that cats have become infected by exposure to dogs with CIV.

CIV has caused localized disease outbreaks around the country. According to veterinary experts, CIV has been reported in more than 30 states plus the District of Columbia. Ask your veterinarian whether the disease has been reported in your area; if it has, please take steps to prevent your dog from contracting it. (See Prevention and Vaccination below.)

CIV is spread between dogs through direct contact (coughing, sneezing, facial licking) or indirect contact (contaminated bowls, leashes, collars, or the hands or clothing of people who handle ill dogs). Virtually all dogs exposed to CIV become infected; however, 20% of dogs don’t show signs but can still spread the virus. Infected dogs usually develop signs of illness within 2 to 4 days. If your dog has been to a place (kennel, hospital, pet or grooming shop, dog park) where the presence of CIV is suspected or confirmed, contact your veterinarian; your dog may need to be quarantined even if he or she doesn’t show signs of illness. If your dog shows signs of a respiratory infection (sneezing, coughing, nasal discharge, fever), you should keep him or her away from other dogs and contact your veterinarian.

Diagnosis

Canine influenza cannot be diagnosed by signs alone because the signs (coughing, sneezing, nasal discharge, fever) are similar to those of other respiratory illnesses in dogs. For dogs that have been sick for a short time, veterinarians swab the nose or throat and submit samples to a diagnostic laboratory for analysis. Specific blood testing can also be helpful in making a diagnosis.

Treatment

Because CIV is a virus, the treatment mostly involves supportive care recommended by your veterinarian. Seriously ill dogs may require fluid therapy, but most affected dogs only need to be quarantined at home or in a kennel for 2 weeks while potentially contagious. Antibiotics may be prescribed to prevent or treat a subsequent bacterial infection.

Prevention and Vaccination

Any time your dog spends with other dogs increases your dog’s risk of exposure to CIV, so if an outbreak is occurring in your area, don’t allow your dog to have contact with other dogs. Ask kennel owners, groomers, show event managers, and your veterinarian what their facilities’ policies are regarding disinfection, quarantine, and disease prevention. As with human influenza, frequent hand washing and disinfection may help prevent the spread of CIV. If you think your dog may have been exposed to CIV, isolate him or her and contact your veterinarian.

There are vaccines that can help protect dogs from CIV. The vaccine does not prevent infection, but vaccinated dogs usually don’t become as sick as unvaccinated dogs and do recover more quickly. The vaccine is useful for dogs that may be exposed to high-risk environments, such as kennels, boarding facilities, dog parks, or dog shows. Ask your veterinarian whether your dog should be vaccinated against canine influenza.

Canine Influenza Fast Facts

Unlike most human influenzas, canine flu is not seasonal—it can occur at any time of the year.